The study of mutagenesis, the theme that unites this Program Project, involves intensive analysis of DNA for the nature and frequency of mutations in particular genomic targets. This typically involves sets in the hundreds of isolates. The execution of such experiments and the analysis of data derived from these is costly and time-consuming. The determination of mutational spectra that are intrinsic to the projects demands two types of analyses: accurate DNA fragment length measurements and DNA sequencing. There is a need in the field for detection of mutations in a larger genomic context, to expand the regions that can be surveyed and to detect the types of mutations that have traditionally posed difficulties for molecular analysis, such as large genomic rearrangements. Highly parallel DNA sequencing platforms now provide an opportunity to extend the scope of mutational analysis. Common needs for the Project are DNA analyses that are convenient and high-throughput, both in physical execution and data analysis.The overall goal of this Core is to provide facilities in which state-of-the-art sequence and fragment length analysis can be coordinated, in cost-effective ways and at a scale and speed demanded by the needs of the program project investigators. A key feature of the Core will be protocoldevelopment, user training, centralized quality control, and data analysis tools, centralized on a shared Wiki site and supported through group interactions. Bioinformatic support will be provided to allow investigators to develop appropriate analysis for their unique needs. The establishment of these facilities will maximize resources, promote development and sharing of expertise and will improve the efficiency of each project.